This invention relates to low density three dimensional non-woven abrasive materials for polishing, machining or otherwise treating the surface of a work piece.
The non-woven abrasive materials with which the invention is concerned are of a known general type including a three dimensional web of non-woven fibers randomly intertwined and carrying abrasive particles some of which are at the surface of the web and others of which are distributed within its interior. Binder material secures the fibers together and bonds the abrasive particles to the fibers, with voids remaining within the web constituting a substantial portion of the total volume of the web.
These prior art non-woven abrasive materials have enjoyed wide scale acceptance for many polishing, grinding and machining purposes, but have had some significant disadvantages in use. For example, when the abrasive material is in the form of a disc driven rotatively in a polishing or grinding operation, conventional discs have tended to "walk" away from a desired point of contact with a work surface, in a manner requiring excessive effort to hold the disc in place and to otherwise control the surface treating operation. Chatter, vibration and irregular oscillation of the tool may further limit the operator's control and disrupt the uniformity of the surface finish.
When the prior art material is utilized to abrade aluminum, it is found that the abraded aluminum metal tends to fuse onto and encapsulate the abrasive particles of the non-woven abrasive material, in a manner preventing the particles from effectively cutting the work surface, thereby adversely affecting the abrading capability of the non-woven abrasive material, many times to the extent of rendering it useless. This encapsulating effect is referred to as "capping" or "loading" in the art, and has greatly limited the usefulness of such non-woven materials for abrading aluminum.